Answers

Hi there, I'm no expert, but I think the plant nurseries force them under lamps for 14 hours a day, or something like that, I'm not sure it's do-able at home, no dout the plant brainiacs will be able to advise you.

If I remember correctly poinsettia need a certain amount of time in total darkness. I cannot remember exactly how long. Other GoYers will be able to tell you how long and when it should be placed in darkness.

They usually need 14 unbroken hours of complete darkness every night, for around 9 weeks--depending on the exact variety. When they have had enough darkness, the new leaves at the tips become a little narrower and denser, and develop a reddish tint. It then takes around 3-5 weeks for the full blown display to develop. Since the different varieties are hardly ever labelled, I usually settle for a show anytime from December 15th to Valentine's day! : )